Method and device for surface processing

ABSTRACT

A method for processing a surface ( 2 ) of a workpiece ( 1 ) is disclosed. Besides, a device for performing the method is disclosed.

RELATED APPLICATIONS

This application claims the benefit of priority of German PatentApplication No. 10 2019 206 431.0 filed on May 3, 2019, and EuropeanPatent Application No. 19 208 741.9 filed on Nov. 12, 2019, the contentsof which are incorporated herein by reference in their entirety.

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to a method and a device for processing asurface of a workpiece, in6 particular, for producing a decorativesurface.

For producing decorative surfaces in the industrial scale, thedecorative surfaces having the aim of reproducing tiles or woodsurfaces, except from a layer forming the later surface, furthermanipulation media are also applied temporarily in order to manipulatethe surface of the layer so that, finally, the decorative surface can beproduced.

For example, EP 3 109 056 A1 describes a method for producing astructure on a surface. Thereto, a liquid layer is applied onto aworkpiece. Subsequently, a manipulation medium in the form of dropletsis sprayed onto the liquid layer, whereby, a displacement of the liquidlayer occurs by the droplets so that recesses together forming astructure in the liquid layer are formed therein. Subsequently, thislayer is fixed. In this way, a surface having a wood or tile look can beproduced on the layer.

EP 3 415 316 A1 discloses a method in which a manipulation medium isapplied onto the liquid layer in the form of droplets or fine droplets,wherein the manipulation medium has the characteristic to at leastpartially absorb electromagnetic radiation. When the liquid layer isirradiated, for example, by an Excimer laser, a polymerization on thesurface of the liquid layer causing a micro folding occurs there,wherein the micro folding has a matt surface as a result later. Thereby,the manipulation medium on the surface of the liquid layer at leastpartially absorbs the radiation so that, here, the polymerization occursless strongly. As a result, these areas are glossier than the areaswhere no manipulation medium was located.

In the known methods, after the performing of the method, in particular,when the layer is at least partially cured, a part of the layer has tobe removed once again in order to achieve the finally desired surfacedesign. In particular, in the production in a production line, this hasto take place quickly so that a high production throughput can beachieved. Also, the device and the method used when removing parts ofthe layer have to be industrially qualified, i.e., it must be possibleto produce at a high availability without too much manual cleaningeffort.

SUMMARY OF THE INVENTION

Therefore, the object of the present invention is to achieve thisproblem.

This object is achieved by the subject-matters of the independentclaims. Advantageous further developments are subject-matter of thesubclaims.

Preferably, a method for removing parts of a layer on a surface of aworkpiece is provided, the method comprising the following steps:

-   -   establishing a mechanical contact between a contact element and        the layer on the surface of the workpiece for removing parts of        the layer;    -   physical separating of removed parts of the layer from the parts        of the layer remaining on the surface of the workpiece.

Alternatively or additionally, a method for removing parts of a layer ona surface of a workpiece is provided, the method comprising thefollowing steps:

-   -   generating a fluid flow for removing parts of the layer;    -   physical separating of removed parts of the layer from the parts        of the layer remaining on the surface of the workpiece.

Thereby, the fluid flow impinges on the layer, preferably, at an anglebetween 1° and 90°.

Preferably, a combination of the two preceding methods to one entiremethod is provided, wherein each of the steps of the methods is executedat least once.

Preferably, the layer on the surface of the workpiece has differences inhardness of at least a factor 1.5, preferably of at least a factor 2,between harder areas and the less hard areas.

As hardness of the layer, in particular, the scratch hardness or thestretch resistance of the layer shall be understood. As long as thesecannot or can only hardly be measured in a possible embodiment due to alow viscosity of the layer or of parts of the layer, alternatively, thepercentage ratio of chemical bonds transformed by polymerization can beunderstood as the hardness described here.

Alternatively or additionally, the layer on the surface of the workpiecehas differences in viscosity of least a factor I.5, preferably of atleast a factor 2, between the higher viscous areas and the less highviscous areas.

Preferably, the physical separating of the removed parts of layer fromthe parts of the layer remaining on the surface of the workpiece isperformed by sucking away, wiping away, blowing away, or by acombination of these steps.

Preferably, the layer located on the surface of the workpiece and thecontact element move relatively with respect to one another whenremoving the parts of the layer.

Preferably, the contact element comprises a stationary and/or a movedbrush and/or a grinding element and/or a plane element, wherein,preferably, the brush, at least as a moved brush, comprises a disk brushand/or a roller brush and/or a brush band and/or, as stationary brush, abeam having a brush trimming, and/or wherein the contact element,particularly the brush, comprises textile and/or plastic fibers, inparticular, nylon fibers, Anderton, and/or metal, particularly steel,brass, or copper as bristles.

Preferably, simultaneously with establishing the mechanical contactbetween the contact element and the layer on the surface, and/orsimultaneously with the generating of the fluid flow onto the layer, anirradiation of the layer and/or of the contact element and/or of thesurroundings of the contact element in which the separated parts of thelayer are located is performed. The irradiation is preferably performedby electromagnetic radiation.

Preferably, the contact element is cleaned continuously during thephysical separating, wherein the cleaning is preferably performed by theuse of a combination of an electromagnetic beam source and/or a suctiondevice and/or a mechanical chipping edge.

Preferably, a nozzle configured to generate a fluid flow is continuouslycleaned during the physical separating, wherein the cleaning ispreferably performed by a combination of an electromagnetic beam sourceand/or a suction device and/or one or several further drying devices orbeam sources. Thereby, the one or several drying devices and/or beamsources can also be located within the one or several suction devices.

Preferably, before establishing the mechanical contact between thecontact element and the layer, cleaning of the surface of the layer isperformed. Alternatively or additionally, after the physical separatingof parts of the layer, a cleaning of the residual layer remaining on thesurface of the workpiece is performed.

Preferably, before the generating of the fluid flow onto the layer,cleaning of the surface is performed. Alternatively or additionally,after the physical separating of parts of the layer, cleaning of theresidual layer remaining on the surface of the workpiece is performed.

Preferably, the continuous cleaning of the contact element, particularlyof the brush, is performed by an irradiation with UV radiation,preferably at a wavelength between 180 and 400 nm, in combination with astripping off of cured residual components of the separated parts of thelayer on a chipping edge and a suctioning away of these residualcomponents by means of a suction device.

Preferably, the continuous cleaning of the nozzle takes place byirradiation with UV radiation, preferably at a wavelength between 180and 400 nm, in combination with a suctioning away of residual componentsof the separated parts of the layer by means of a suction device.

Preferably, for cleaning the surface of the layer, a cleaning agentbeing preferably subsequently removed, in particular, preferably bymeans of a stripper and/or a suction device, is applied onto the layer.The cleaning agent is preferably liquid until pasty. The cleaning agentis configured to enclose debris and dirt on the surface of the layer,wherein, subsequently, removing of the cleaning agent with the encloseddebris and dirt can be performed.

Except from the pure processing of the layer on the workpiece, adeployment of a manipulation medium can be provided.

Preferably, a method for producing a decorative surface on a workpieceis provided, the method having the following steps:

-   -   applying a manipulation medium at least onto and/or into a part        of a liquid layer located on the workpiece and/or at least on a        part of the workpiece;    -   removing parts of the layer, wherein the removing is performed        mechanically and/or in a contactless, particularly fluidic,        manner.

Thus, a manipulation medium is applied onto and/or into an at leastpartially liquid layer located on a workpiece. The manipulation mediumcan alternatively or additionally also be applied onto the workpieceitself. The applying of the manipulation medium thereby is performedpreferably on subareas or sections of the liquid layer and/or of theworkpiece. In the further proceeding of the method, parts of the layerare removed. The removing is preferably performed mechanically and/or ina contactless, particularly fluidic, manner. If the manipulation mediumis applied directly onto the workpiece, preferably subsequently, theliquid layer is applied as described below. Preferably, before theremoving of parts of the layer is performed, the layer together with themanipulation medium is dried and/or at least partially cured so that theviscosity of the layer increases.

These method steps can be provided in a method for producing adecorative surface on a workpiece. Between the execution of the removingof parts of the layer and the method steps performed before, however, atimely brake can be so that, particularly the removing of parts of thelayer, can be an autonomous method.

Preferably, the parts of the layer which are removed also comprise partsof the manipulation medium located on or in the layer. In a specificembodiment, it is purely about the manipulation medium. If themanipulation medium is removed from the layer, this can be performedpartially so that a residual of the manipulation medium remains on or inthe layer.

However, the removing can also be performed completely so that themanipulation medium is completely removed.

Thus, the removing of parts of the layer can involve that the materialof the layer itself is removed. Alternatively, also only themanipulation medium can be removed from the layer. However, also both,therefore, the material of the layer itself and the material of themanipulation medium can be removed.

Preferably, the mechanical removing of parts of the layer is performedby a removal device comprising a contact element being in contact withthe layer, wherein the surface of the layer and the contact element moverelatively with respect to one another.

Besides an opposite motion, a unidirectional or a motion formed inanother manner can occur.

Preferably, the contact element comprises a stationary and/or a movedbrush and/or a grinding element and/or a plane element, wherein thecontact element is provided in a moving or stationary manner withrespect to the workpiece. Preferably, at least as moved brush, the brushcomprises a disk brush and/or a roller brush and/or a brush band and/or,as stationary brush, a beam having a brush trimming.

The grinding element and/or plane element is preferably configured toskim parts of the layer once again in order to expose the manipulationmedium enclosed therein. Subsequently, the manipulation medium can beremoved by means of the grinding element and/or the plane element or bymeans of other methods described here. The grinding element canpreferably include a belt sander.

Generally, the contact element can comprise a stationary and/or a movedelement. The contact element is further preferably designed as acyclically working contact element, for example, comprising an abrasivebelt or a roller brush. Thereby, the contact element preferablycomprises portions which are cyclically not in contact with the layerduring the removing. As described below, these portions can be cleanedat this moment.

Preferably, the contact element, particularly the brush, comprisestextile and/or plastic fibers, in particular, nylon fibers, and/ormetal, in particular steel, brass, or copper.

Moreover, fibers including abrasives can be deployed. Hereby,preferably, it's about fibers with Anderton. These fibers or materialsare preferably included in the bristles of the brush. Thus, inparticular, configurations of the brush having metal or plastic bristlesare possible.

The brush preferably comprises bristles having a diameter of 0.05 to 2mm, preferably 0.1 to 1.2 mm, further preferably 0.2 to 0.7 mm,especially preferred 0.2 to 0.3 mm.

Preferably, the removing of parts of the layer includes suctioning awaythe parts by vacuum, preferably by means of a suction device, and/orheating of the layer and/or of the manipulation medium, preferably, bysupplying heat, particularly preferred for at least partial liquidationof the parts of the layer, particularly of the manipulation medium.Preferably, the heat supply can be performed by a heater or an IRradiator.

Preferably, a controlled and/or regulated motion of the contact elementis performed. This can be, for example, the positioning of the contactelement relative to the layer or, also, an adjustment of the number ofrevolutions or of the velocity of circulation of the disc brushes or ofthe brush band.

While the contact element removes parts of the layer, clogging of thecontact element by the removed material of the layer and/or of themanipulation medium can occur. In the case of a brush, this means thatthe removed material settles in the bristles. As the case may be, agrinding element and/or a plane element can also be affected by theclogging. Therefore, a further step in which cleaning of the contactelement is performed can be provided. The entire method for cleaning thecontact element which is described below can also be executedindependently from the method described in this application.

The cleaning can preferably be performed by mechanically stripping awaythe material on a stripping edge and/or also by means of suctioning awayby vacuum, e.g., by the above mentioned or a further suction device.

In order to reduce the viscosity of the material and/or of themanipulation medium and, thereby, to improve the detachability from thecontact element, also here, a supply of heat to the contact element canbe provided. The supply of heat can preferably be performed by a heateror by an IR radiator. For example, the heater can be provided in thecontact element.

Alternatively or additionally, the cleaning of the contact element caninclude that the contact element is irradiated by radiation, inparticular, electromagnetic radiation and/or electron radiation, duringthe removing of the manipulation medium and/or of parts of the layerapplied before. Thereby, in particular, it is achieved, that thematerial settled on the contact element is at least partly or completelycured and, then, exists in a hard and brittle form. Preferably, by thehardening of the material, it is achieved that it easily breaks loosefrom the contact element, in particular, from the bristles if a brush isprovided. By mechanically stripping away and/or sucking away, thismaterial can be removed from the contact element once again.

For the mechanical stripping away, for example, a stripping edge atwhich the clogged contact element can be passed can be provided, wherebythe manipulation medium and/or the removed part of the layer can bestripped away. If, for example, the contact element comprises a brush,therefore, for this purpose, the bristles of the brush can come incontact with the stripping edge.

Except from the radiation hardening, further hardening methods can alsobe deployed in order to cure the material which has clogged the contactelement. In general, various methods can be deployed in order toinfluence particularly the viscosity and/or the rigidity of materialclogging the contact element. With contact elements cyclically working,it is important that the removing of parts of the layer as well as thecleaning of the contact element, therefore, the removing of these partsof the layer from the contact element, are performed within one cycle.Consequently, the influence on the viscosity, if it is performed in themethod, has to be performed within this cycle. Since the materialclogging the contact element is, in particular, material of the layerand/or of the manipulation medium, therefore, each method causing acuring or a change of the viscosity of these materials can be deployedbasically. Therefore, there is a hint to the possibilities described inthis application.

In a preferred embodiment, the material and/or the manipulation mediumcomprises a ratio of more than 70% of acrylates cross-linking byirradiation by electromagnetic radiation via the generation of chemicalbonds and, therefore, the acrylates reduce the viscosity and, therefore,also the adhesiveness of the material and/or of the manipulation mediumand increase the brittleness. Therefore, the above-described embodimentof the cleaning of the contact element is well suited to ensure anenduring and less failure-prone operation of an industrial facilityproducing according to the method of the invention.

In other embodiments, the material and/or the manipulation medium canalso comprise other components, as, e.g., an aqueous mixture withbonding agents, pigments, and other additives, or can be constitutedthereof.

Preferably, the removing of parts of the layer comprises a streamingonto the surface of the layer and/or of the manipulation medium by afluid flow, in particular, by an airflow. In this way, in particular,the manipulation medium can be removed in a contactless manner which ispreferably gentle for the surface of the layer. Therefore, alsoworkpieces comprising elements which can be damaged by non-contactlessmethods, e.g., by the contact with an above-described brush, can beprocessed. For clarification, in FIG. 6, an embodiment of such aworkpiece is shown. Here, a workpiece 1 in the form of a pre-milledplank having a layer 2 applied onto the workpiece surface is shown.Leftwards, the workpiece 1 comprises a connection element 1 a which canengage in a slot of a further workpiece in the sense of a slot and keyconnection in order to join together several workpieces in this way,e.g., as a flooring material. According to the state of the art, insteadof slot and key, today, so-called “click-profiles” which are, e.g.,illustrated in EP 2 280 130 A2, are used for the installation of thefloor planks. These areas or also the transition area from theconnection element towards the layer 2, probably, should not needlesslybe mechanically stressed during the production. Therefore, particularlyhere, a contactless removing of parts of the layer is preferable.

Furthermore, the method can preferably also be used for surfaces outsidethe floor covering, e.g., for furniture, wall, ceiling surfaces or alsofor external facade elements or further applications.

Preferably, the fluid flow impinges on the surface of the layer and/orof the manipulation medium in an accordingly formed manner so that itextends across the entire width of the layer. The length of theextension of the impingement area of the fluid flow in the direction ofmotion of the workpiece is preferably 1% to 20%, especially preferred 5%to 15%, particularly 10% to 12%, of the length of the extension of thefluid flow across the direction of motion. Thus, a fluid flow as thin aspossible, in particular, in the sense of an “air blade” or an “airknife”, is preferably used. Alternatively, a liquid flow, particularlycontaining water, can also be used as fluid flow.

Preferably, the fluid flow impinges on the layer and/or the manipulationmedium at an angle less than 45°, preferably less than 30°, especiallypreferred less than 15°. In case that, for example, only themanipulation medium shall be detached, in particular, in the case ofapplication of merely a manipulation medium onto the surface of thelayer, a flat inflow is useful to achieve detachment from the layer.Depending on the situation, however, a steeper adjustment of the fluidflow can also be useful in order to, e.g., blow away a manipulationmedium which is contained in recesses of the layer. Preferably, theangle is particularly cyclically varied during the execution of themethod. The variation can preferably also be depending on the currentlydetected amount of the removed manipulation medium. This amount ispreferably detected by a detection device, for example, detecting theweight of the removed manipulation medium.

Alternatively or additionally, the fluid flow can impinge on the surfaceof the layer also by so-called rotation nozzles. Thereby, with an entirediameter of the rotating nozzles of preferably 2-120 mm, especiallypreferred 5 to 50 mm, the rotation nozzles guiding the fluid flow to thesurface rotate about a central axis. Thereby, a timely variable fluidflow is directed to the surface.

Preferably, the fluid flow further contains solid bodies enhancing theremoving of parts of the layer. For example, sand or a comparablesubstance for additionally acting on the surface of the layer and/or ofthe manipulation medium besides the fluid flow can be included here. Thefluid flow can particularly also be used, besides the manipulationmedium, to remove also material from the layer.

The solid bodies have a diameter of preferably 0.0001 to 1 mm, preferred0.001 to 30.5 mm, especially preferred 0.005 to 0.3 mm.

Alternatively or additionally, the solid bodies are configured toliquefy or to evaporate after the impingement on the layer and/or themanipulation medium. This can, for example, be achieved thereby that thesolid bodies have the property to evaporate in the ambient temperatureto which the workpiece including the layer is exposed. For example, thiscan be achieved by solid bodies of dry ice. These solid bodies of dryice can particularly be applied onto the surface of the layer and/or ofthe manipulation medium by a dry ice beamer. Thereby, it is preferablyachieved that the solid bodies do not remain on and/or in the layer.Thus, a subsequent removing of the solid bodies from the layer can beomitted.

Alternatively or additionally, the solid bodies can be supposed to besupplied with a liquid, particularly with water, during the generatingof the fluid flow. Thereby, an increase of the mass of the solid bodiesis achieved so that the effect to the surface of the layer and/or themanipulation medium is increased. The supply can be performed, e.g., bymoving the solid bodies with the fluid flow through a fog of the liquid.Thereby, the solid bodies act as cloud condensation nuclei at which thecomponents of the fog inhere, whereby, the supply of the solid bodies bythe liquid is performed finally.

Particularly, the solid bodies can comprise sand grains, dry ice (solidCO₂), water ice (frozen water), sodium bicarbonate, or mixtures of thesecited solid bodies.

Preferably, the method further comprises at least one of the followingsteps:

-   -   applying a liquid layer onto at least a part of a surface of the        workpiece and/or onto a manipulation medium applied onto the        surface of the workpiece;    -   curing the layer and/or the manipulation medium at least until        partial curing.

In a specific embodiment, a method comprising this procedure isprovided:

-   -   applying a liquid layer onto at least a part of a surface of the        workpiece and/or onto a manipulation medium applied onto the        surface of the workpiece;    -   applying the manipulation medium at least onto a part of the        liquid layer and/or into the liquid layer and/or at least onto a        part of the workpiece;    -   curing the layer and/or the manipulation medium at least until        partial curing;    -   removing the manipulation medium as described above.

The layer and/or the manipulation medium is preferably configured to bepolymerizable by means of electromagnetic radiation.

In a further specific embodiment, a method comprising the followingprocedure is provided:

-   -   applying a liquid layer onto at least a part of a surface of the        workpiece;    -   applying the manipulation medium onto at least a part of the        liquid layer and/or into the liquid layer;    -   curing the layer and/or the manipulation medium at least until        the partial curing;    -   removing parts of the layer as described above.

In this last-named embodiment, by the last step (removing parts of thelayer), the applied manipulation medium can also be completely orpartially co-removed commonly.

In each conceivable embodiment of the method, in particular, in the twojust described specific embodiments, further method steps which can beprovided before, between and also after the heretofore described methodsteps can be provided. Moreover, individual method steps can also berepeated.

Preferably, the manipulation medium comprises water. In a specificembodiment, the manipulation medium consists exclusively of water.

Preferably, the layer and/or the manipulation medium comprises acrylatecontaining material.

During the execution of the method, the workpiece is preferably moved ina direction of motion and, therefore, it is supplied successively toelements of a device, wherein the elements are designed to execute theindividual method steps. Alternatively or additionally, the elements ofthe device can be configured to move with respect to the workpiece.

For example, the method can be performed such that the layer is appliedin a liquid form onto the surface of the workpiece. Subsequently, themanipulation medium is applied onto and/or into the layer. However, themethod can also be configured such that the manipulation medium is firstapplied onto the surface of the workpiece. Subsequently an applicationof the layer is performed. Here, the manipulation medium functionspreferably as placeholder so that regions of the surface of theworkpiece do not contact the layer. If the manipulation medium isremoved after the layer has been cured, these places remain asindentions or recesses in the layer. Of course, embodiments in which anapplication of the manipulation medium before as well as after theapplication of the layer is performed are conceivable. Also, a repeatediteration of the application of the layer and/or the manipulation mediumis possible. If the manipulation medium is used as placeholder, themanipulation medium is preferably cured before the application of theliquid layer.

Before the application of the manipulation medium, drying or curing ofthe liquid layer, preferably by electromagnetic radiation at awavelength of 200 to 400 nm, is performed, particularly to influence theviscosity of the liquid layer.

Preferably, after the application of liquid layer, the manipulationmedium is applied onto parts of the liquid layer.

Preferably, the manipulation medium and the at least partially liquidlayer are irradiated by electromagnetic radiation, preferably at awavelength of 180 to 400 nm.

Moreover, the curing can also be executed several times. For example, afirst curing of the layer until the partial curing can be executedbefore the manipulation medium is applied. In this way, a desiredviscosity of the layer can be pointedly adjusted so that, for example, astructure arising by the application of the manipulation medium enduresfor a certain time before the structure melts.

Preferably, the curing contains an irradiation of the layer and/or ofthe manipulation medium by electromagnetic radiation, preferably by UVradiation and/or by irradiation by electron radiation.

The curing can preferably be performed at the same time as the removingof parts of the layer. For example, the place of the layer which is justin contact with the contact element can simultaneously be irradiatedwith UV radiation causing the curing. The same is valid for allpossibilities removing in a mechanical or contactless manner asdescribed above.

The manipulation medium covering parts of the layer can cause that thecovered part of the layer does not cure in the same extent as theexposed parts. Thereby, in particular, it can concern about the heredescribed methods for curing. After the removing of parts of the layer,then, a final curing of the remaining layer and/or the remainingmanipulation medium is executed.

Alternatively or additionally, the curing includes active and/or passivedrying. By active drying, in the following, each kind of drying in whichthe liquid layer is dried by generating specific conditions isunderstood. Therefore, the liquid layer and/or the manipulation mediumcan particularly be dried by means of incident flow of a fluid,particularly of air, and/or by supplying heat, particularly by means ofIR radiation or by use of a heater.

Whereas, passive drying is preferably characterized in that the liquidlayer and/or the manipulation medium cures for itself and without anyfurther processing. This can, e.g., take place by a transport of theworkpiece on a free track section of a conveyor transport and/or bydepositing the workpiece.

Preferably, the curing by means of reaction curing takes place by, e.g.,a two-component system which cures by a chemical reaction between thecomponents of the layer and/or the manipulation medium within less than30 minutes, preferably less than 5 minutes.

Preferably, the layer is cured after the application of the manipulationmedium in such a way that the viscosity of places of the layer where themanipulation medium has been applied differs from the viscosity of theplaces where the manipulation medium has not been applied. Preferably,the difference corresponds to a factor of at least 1.5, especiallypreferred to a factor of at least 2. Preferably, the viscosity at placeswhere the manipulation medium has been applied is less than at placeswhere the manipulation medium has not been applied. In the case ofradiation curing, this is justified thereby that the layer underneaththe manipulation medium has been, at least partially, shielded from theradiation, whereby the layer has been exposed to a lesser amount ofradiation and, thus, cured less.

Preferably, the curing of the layer until the final curing of the layeris performed after the removing of parts of the layer.

Preferably, the layer is at least partially cured before the applicationof the manipulation medium. If the manipulation medium has been appliedbefore the liquid layer, also the manipulation medium can be at leastpartially cured, whereby preferably electromagnetic radiation, inparticular UV radiation, is respectively used thereto. The curing isthereby preferably executed as described above.

Preferably, the applying of the liquid layer onto the workpiece isperformed by a digital and/or analog procedure. Particularly preferred,the application of the liquid layer onto the entire surface of theworkpiece is performed. In an analog procedure, the application can takeplace by means of an application roller or of a casting machinegenerating a liquid carpet of the material of the layer, wherein thework piece is moved through the carpet. An application roller and acasting machine have the advantage that the layer can be applied onto anarea as broad as possible at small efforts. In a digital procedure, theapplication is performed by means of a digital printing technique, e.g.,by a digital printing head or a digital nozzle beam. Thereby, the layercan also be applied only onto sub-areas of the workpiece.

Preferably, the application of the manipulation medium onto theworkpiece and/or onto the liquid layer is performed by a digitalprocedure. Thereto, a digital printing technique, for example, with adigital printing head or a digital nozzle beam is deployed. Thereby, themanipulation medium to be applied can be deployed especiallyeconomically and precisely. However, an analog technique, as, e.g., acasting device, is also conceivable.

Preferably, the application of the manipulation medium includes anapplication of the manipulation medium in the form of droplets and/or inthe form of fine droplets. The application of the manipulation mediumonto the layer in form of droplets is preferably performed such that thedroplet speed and/or the droplet volume is controlled such that recessesare brought into the layer by the droplets, wherein the recessespreferably have a depth of preferably 2 μm to 100 μm, especiallypreferred from 3 μm to 50 μm.

The emission of the fine droplets is preferably controlled such thattheir momentum when impinging on the surface of the liquid layer is notsufficient for at least partially overcoming the surface tension and/orthe viscosity forces of the liquid layer so that the fine dropletspreferably come to lie on the surface of the liquid layer. Especiallypreferred, the manipulation medium is applied onto the surface of thelayer in the form of fine droplets as fog so that this fog formsparticularly closed areas covering the surface of the layer.

Thereby, the fine droplets particularly have a volume from 0.1 pl to 1pl, preferably from 0.3 to 0.8 pl, especially preferred from 0.5 to 0.6pl.

Thereby, the droplets particularly have a volume from 1 pl to 80 pl,preferably from 3 pl to 12 pl, especially preferred from 5 pl to 10 pl.

The speed of the droplets and/or of the fine droplets is particularlybetween 0.5 m/s and 12 m/s, preferably between 3 m/s and 7 m/s,especially preferred between 5 m/s and 6 m/s.

The speed and/or the volume of the droplets and/or of the fine dropletscan be varied during the applying of the manipulation medium.

The emission of the droplets is preferably controlled such that theirmomentum when impinging on the surface of the liquid layer is sufficientfor at least partially overcoming the surface tension and/or theviscosity forces of the liquid layer so that a displacement of theliquid layer ensues by the droplets, whereby recesses and, inparticular, a structure of 10 to 15 μm difference in height can bebrought in.

Preferably, the manipulation medium is configured to at least partiallyabsorb incident electromagnetic radiation, whereby, preferably at least10%, especially preferred at least 30%, particularly at least 50%, ofthe incident electromagnetic radiation are absorbed. In this way, it ispossible to shield the surface of the layer at least partially from theelectromagnetic radiation so that, in particular, during curing of theliquid layer, the electromagnetic radiation acts varyingly strong on thesurface of the layer. Compared to the exposed spots, the electromagneticradiation acts weaker at the places of the layer covered by themanipulation medium. Therefore, if, e.g., a wavelength of less than 300nm, preferable less than 250 nm, especially preferred less than 200 nm,is used, a micro folding on the surface of the layer can be generated,wherein the micro folding turns out weaker at the places of the layercovered by the manipulation medium than at the exposed places. As aresult, the places which, during this irradiation, have not been coveredwill appear more matt than the places which have been covered by themanipulation medium. Specifically, a wavelength of 185 nm is used here.The irradiation preferably takes place in a protective gas atmosphere,in particular, in a N₂ atmosphere.

Preferably, the manipulation medium and the layer are configured not tocoalesce to each other during the curing. Thereby, the particularlycomplete removing of the manipulation medium is considerablyfacilitated.

Preferably, a device for performing the above mentioned method isprovided, the device comprising:

-   -   a transport device configured to transport a workpiece to        further elements of the device and/or to move at least a further        element of the device to the workpiece; and    -   as further element, a removal device configured to remove parts        of the layer in a mechanical manner, preferably by a contact        element, and/or a fluidic manner, preferably by a fluid flow        from a nozzle, wherein    -   the device further comprises a control means configured to        control the transport device and the further elements of the        device in order to perform the method described above.

Further, preferably, a device for performing the above mentioned methodsis provided, the device comprising:

-   -   a transport device configured to transport a workpiece to        further elements of the device and/or to move at least one        further element of the device to the workpiece; and    -   as further element, an application device, in particular,        comprising a digital printing device configured to apply a        manipulation medium onto an at least partially liquid layer        located on the workpiece and/or onto a surface on the workpiece;    -   preferably as further element, a curing device configured to        cure the liquid layer and/or the manipulation medium; and    -   as further element, a removal device configured to remove parts        of the layer in a mechanical and/or fluidic manner, wherein    -   the device further comprises a control means configured to        control the transport device and the further elements of the        device in order to perform one of the methods as described        above.

The device can particularly comprise device features or configurationsdescribed above in the elucidation of the method.

Preferably, the transport device comprises a conveyor transport deviceon which the workpiece can be transported to the further elements of thedevice. Alternatively or additionally, it can also be configured suchthat at least one of the elements of the device is moved to theworkpiece.

Preferably, the curing device comprises a radiation source forelectromagnetic radiation, wherein the wavelength of the emittedradiation is preferably variable. Especially preferable, the emittedradiation is UV radiation.

Preferably, the curing device comprises a blower configured to blow afluid flow, particularly an airflow, onto the layer and/or onto themanipulation medium in order to perform drying of the layer and/or ofthe manipulation medium.

Preferably, the removal device comprises a contact element formechanical removing the contact element being configured to contact thesurface of the layer and/or of the manipulation medium in order toremove parts of the layer.

Preferably, the removal device comprises a nozzle configured to let flowa fluid flow, preferably, an airflow, onto the surface of the layer inorder to remove parts of the layer, in particular, the manipulationmedium. The fluid flow is preferably configured as described above. Thenozzle is preferably designed as being movable in order to be able tovary the angle at which the fluid flow impinges on the surface of thelayer.

Preferably, the removal device comprises a suction device designed suchthat the manipulation medium is sucked from the layer by means of vacuumand/or already loosened parts of the layer, in particular, themanipulation medium, are sucked away.

Preferably, the suction device comprises a suction nozzle which isespecially particularly designed as being movable and which can beapproached to the surface of the layer in order to suck away themanipulation medium.

Preferably, the device comprises a chamber in which at least the nozzleand/or the suction nozzle is provided in order to collect loosened partsof the manipulation medium.

Preferably, the removal device comprises a heating device configured toheat the surface of the layer and/or the manipulation medium.Alternatively or additionally, the heating device can be configured totransmit heat to the contact element in order to prevent or reduceclogging of the contact element as described above. It can also beprovided that the contact element comprises the heating device.Preferably, the heating device comprises an IR radiator.

Preferably, the contact element comprises a stationary and/or a movedbrush and/or a grinding element and/or a plane element. Preferably, thecontact element, particularly the brush, comprises textile and/orplastic fibers, particularly nylon fibers, and/or fibers of metal,particularly steel, brass, or copper. Apart from that, the contactelement can be configured as described above. Further, the contactelement can comprise fibers including a grinding means.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Below, the invention is described in detail by means of preferredembodiments and by means of the attached drawings.

In particular,

FIG. 1 shows an embodiment of the invention in which the removing ofparts of the layer is performed in a fluidic manner;

FIG. 2 shows an embodiment of the invention in which the removing of theparts of the layer is performed in a mechanical manner;

FIG. 3 shows an embodiment of brushes for mechanical removing of partsof the layer;

FIG. 4 shows a further embodiment of brushes for mechanical removing ofparts of the layer;

FIG. 5 shows a further embodiment of brushes for mechanical removing ofparts of the layer;

FIG. 6 shows a workpiece in the form of a pre-milled plank having anapplied layer;

FIG. 7 shows a possibility for cleaning the contact element;

FIG. 8 shows a device in the form of a production line;

FIG. 9 shows a possibility for cleaning the surface of the layer;

FIG. 10 shows a cross-section of a workpiece having a layer comprisingdifferent hardness grades; and

FIG. 11 shows an exemplary flowchart of a method.

DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

FIG. 1 shows an embodiment of the invention in which the removing ofparts of the layer, here, in particular, the manipulation medium, isperformed in a fluidic manner.

A flat workpiece 1 moving from the right to the left in the drawing isshown. The workpiece 1 is covered by a liquid layer 2 forming thesurface of the workpiece 1 after the complete curing. Into the liquidlayer 2, a manipulation medium 3 has been brought in at some places inorder to displace the liquid layer 2. The workpiece 1 is moved into achamber 4, for example, by a transport device of a device according tothe invention. The chamber 4 comprises, in the direction of motion,first, a curing device 5 comprising an UV radiation source emitting UVradiation onto the liquid layer 2 in order to cure it so that theviscosity of the layer 2 is changed. The UV radiation has thereby awavelength of 200 to 400 nm. Subsequently, the workpiece 1 is fed to anozzle 6 emitting a fluid flow against the direction of motion at anangle with respect to the surface of the layer 2. Thereby, the angle ismaximum 45° or less. Preferably, an adaption of the angle between 0° and45° is performed. This adaption can be done, for example, depending onthe removed manipulation medium.

By the nozzle 6, the fluid flow is formed such that it exerts a flowpressure onto the manipulation medium 3, wherein the flow pressure is ashigh as the manipulation medium 3 breaks loose as part 13 of the layer 2from the layer 2.

By the pressure of the fluid flow, subsequently, the loosened parts 13of the manipulation medium 3 (framed in a dotted manner) are urged tothe right where they are collected by a suction device 7 by vacuum andremoved from the chamber 4.

In one embodiment, the fluid flow is configured such that it extendsacross the entire width of the workpiece 1, i.e., in a direction ofextension of the workpiece 1 perpendicular to the drawing plane. In thisway, it is ensured that all of the parts of the manipulation medium 3are covered by the fluid flow which, in particular, upon a chaoticallyor irregularly inserted manipulation medium 3, obviates the need of atargeted streaming to individual regions of the surface of the layer 2.

As fluid, a liquid or a gaseous substance is deployed. Specifically,also, water and/or air can be deployed as the fluid.

FIG. 2 shows an embodiment of the invention, in which the removing ofparts of the layer is performed in a mechanical manner.

A flat workpiece 1 moving from the left to the right in the drawing isshown. The workpiece 1 is covered by a liquid layer 2 forming thesurface of the workpiece 1 after the complete curing. Into the liquidlayer 2, a manipulation medium 3 has been brought in at some places inorder to displace the liquid layer 2. The workpiece 1 is, for example,moved by a transport device of a device according to the invention.

In the direction of motion, first, a suction device 7 configured to suckaway loosened parts 13 of the layer 2, in particular, the loosedmanipulation medium 3, by means of vacuum is arranged. Thereto, thesuction nozzle of the suction device 7 is aligned close to the surfaceof the layer 2. After the suction device 7, a brush 8 designed as rollerbrush is arranged. This brush 8 extends perpendicular to the drawingplane across the direction of motion of the workpiece 1. In thisembodiment, the roller brush is rotated opposite to the direction ofmotion of the workpiece 1. The suction device 7 further comprises aradiation source 12. This radiation source 12 is configured to emitelectromagnetic radiation, such as UV radiation, for curing thesucked-up parts 13 of the layer 2, whereby, curing of the parts 13 takesplace within the suction device 7 so that there is no risk for adheringin and clogging the suction device 7.

By the contact of the bristles of the brush 8, parts 13 of the layer 2,in particular, the manipulation medium 3, are brushed away from thelayer 2 and conveyed in direction of the suction device 7. This suctiondevice 7 collects the loosened parts 13 (framed in a dotted manner).

Finally, a further radiation source 12 a configured to emitelectromagnetic radiation, particularly UV radiation, to the brush 8 inorder to cure and/or embrittle the material of parts of the layer 2adhering there in order to clean the brush 8 is shown.

FIG. 3 shows an embodiment of brushes for mechanical removing of partsof the layer.

A workpiece 1 as well as several brushes 8 are shown in plan view. Theworkpiece 1 is moved through under the brushes 8 from the left to theright. The brushes 8 are here designed as disc brushes rotating in theshown directions of rotation 9 around a respective axis. When theworkpiece 1 on which a layer with or without a manipulation medium (bothis not shown) is located is moved through under the brushes 8, thus,parts of the layer, in particular, the manipulation medium, aremechanically removed by a contact with the brushes 8 relatively movingwith respect to the workpiece 1.

By the rotating motion of the brushes 8, additionally to the relativemotion between the workpiece 1 and the brushes 8, a further relativemotion component is added so that the force by which the bristles of thebrushes 8 act onto the layer or the manipulation medium is enlarged.

FIG. 4 shows a further embodiment of brushes for mechanical removingparts of the layer, in particular of the manipulation medium.

A workpiece 1 having a layer with or without a manipulation medium (bothis not shown) as well as a brush band are shown in the side view. Theworkpiece 1 is moved from the left to the right. The brush band istrimmed with several brushes 8.

The brush band cyclicality circulates in the shown circulation directionso that the brushes 8 which are located at the underside of the brushband at the moment move from the right to the left opposite to themotion of the workpiece 1. In this way, additionally to the relativemotion between the workpiece 1 and the brushes 8, a further relativemotion component is added due to the motion of the workpiece 1 from theleft to the right so that the force by which the bristles of the brushes8 act onto the layer or the manipulation medium is enlarged.

FIG. 5 shows a further embodiment of brushes for mechanical removing ofparts of the layer, in particular, of the manipulation medium.

A workpiece 1 which is moved through from the left to the right under abeam 11 comprising, on its side facing the workpiece 1, brushes whichcan contact the workpiece 1 or the layer and/or the manipulation mediumthereon (both is not shown) is shown in the plan view. Thereby, the beam11 extends across the entire extension of the workpiece 1, therefore,from above to below in the drawing.

FIG. 7 shows a possibility for cleaning the contact element.

A flat workpiece 1 which is moved from the left to the right in thedrawing is shown. The workpiece 1 is covered with a liquid layer 2 whichforms the surface of the workpiece 1 after the complete curing. Into theliquid layer 2, a manipulation medium 3 has been inserted at some placesin order to displace the liquid layer 2. The workpiece 1 is moved, forexample, by a transport device of a device according to the invention.

In the direction of motion, first, a suction device 7 configured to suckaway parts 13 of the layer 2, particularly the loosed manipulationmedium 3, by means of vacuum is arranged. Thereto, the suction nozzle ofthe suction device 7 is aligned close to the surface of the layer 2.After the suction device 7, a brush 8 designed as a roller brush isarranged. This brush 8 extends perpendicular to the drawing plane acrossthe direction of motion of the workpiece 1. In this embodiment, theroller brush is rotated opposite to the direction of motion of theworkpiece 1. Further, the suction device 7 comprises a radiation source12. This radiation source 12 is configured to emit electromagneticradiation, such as UV radiation, for curing the sucked-up parts 13 ofthe layer 2, whereby curing of the parts 13 takes place within thesuction device 7 so that there is no risk that they adhere within thesuction device 7 and clog it.

Apart from that, the functionality of the brush 8 as well as of thesuction device 7 for removing the parts 13 of the layer 2, particularlythe manipulation medium 3, is identical to the functionality of theembodiment in FIG. 2.

For cleaning the contact element or the brush 8, a radiation source 12 aemitting the UV radiation to the brush 8 and, thus, to the parts 13 ofthe layer 2 adhering on the bristles of the brush 8 is provided here,wherein the parts 13 can comprise the material of the layer 2 andmaterial of the manipulation medium 3. In their rotary motion, thebristles of the brush 8 hit onto a stripper edge 14 after they have beenirradiated by the radiation source 12 a. The stripper edge 14 extendsdownright in the drawing and comprises a surface being formed such thatparts 13 of the layer 2 which has been loosed from the bristles, areguided into direction of a suction device 7 a located at this surface.The suction device 7 a is configured to receive the loosened parts 13 ofthe layer 2 and to the suck them away by means of vacuum.

The functionality of the cleaning of the brush 8 presents as follows:

Within a cycle, i.e., within one rotation of the brush 8, the bristlesof the brush 8 first hit onto the surface of the layer 2, whereby, here,parts 13 of the layer 2 are removed. Parts 13 which are loosed and whichdo not adhere in the bristles of the brush 8 are conveyed by the brushin direction of the suction device 7 which sucks them away by means ofvacuum. In the further course of the rotation of the brush 8, parts 13adhered in the bristles of the brush 8 are irradiated by the radiationsource 12 a, whereby they cure. The irradiation of the radiation source12 a can be as strong as the parts 13 adhered in the bristles of thebrush 8 embrittle. Subsequently, the bristles hit onto the stripper edge14, whereby a mechanical effect to these parts 13 is achieved. Due tothat, the cured and/or embrittled parts 13 loose from the bristles ofthe brush 8, whereby they are conveyed by their removal speed and theformed surface of the stripper edge 14 to the suction device 7 a. Thesuction device 7 a finally sucks away these parts 13. The bristles ofthe brush 8 cleaned in such manner are now available again for removingparts 13 of the layer 2 in a new cycle.

FIG. 8 shows a device in the form of a production line.

Two workpieces 1 which are moved one after another in the direction ofmotion from the left to the right are shown. Thereto, a transport device(not shown) is provided. The workpiece 1 comprises a liquid layer 2 onits surface. In and/or on the layer 2, a manipulation medium 3 isincluded. In the direction of motion, following elements are arrangedone after another from the left to the right. First, a stationarycontact element in the form of a brush 15 which is configured to contactthe surface of the layer 2 in order to mechanically remove parts of thelayer 2 is arranged. Thereby, it is here achieved that the manipulationmedium 3 enclosed in the layer 2 is uncovered. After the brush 15, aradiation source 12 configured to emit UV radiation in the direction ofthe workpiece 1 or the layer 2 is arranged in order to at leastpartially cure the layer 2.

Subsequently in the direction of motion, an element comprising a chamber4 through which the workpiece 1 is moved is provided. In the directionof motion, the chamber 4 first comprises a nozzle 6 emitting a fluidflow against the direction of motion of the workpiece 1 at an angle withrespect to the surface of the layer 2. Thereby, the angle is maximum 90°or less. Preferably, an adaption of the angle between 0° and 30° isperformed. This adaption can be performed, for example, depending on theremoved material of the manipulation medium 3 and/or depending on theremoved material of the layer 2. The fluid flow comprises solid bodiesas described above in order to remove parts 13 of the layer 2. Further,the chamber 4 comprises a suction device 7 configured to suck awayloosened parts 13 of the layer 2. Within the chamber 4, in the motiondirection behind the nozzle 6, a radiation source 12 configured toirradiate the layer 2 with radiation in order to partially cure it sothat the viscosity of the layer 2 changes is located. The radiation can,for example, be UV radiation having a wavelength of 200 to 400 nm.

In one embodiment, the fluid flow is configured such that it extendsacross the entire width of the workpiece 1, i.e., in a direction ofextension of the workpiece 1 perpendicular to the drawing plane. In thisway, it is ensured that all areas of the layer 2 are covered by thefluid flow.

A liquid or a gaseous substance is deployed as fluid. Specifically, alsowater and/or air can be deployed as fluid.

After the chamber 4, a contact element having a brush 8 in the form of aroller brush is arranged. The brush 8 is configured to mechanicallyremove parts of the layer 2. A radiation source 12 a, for example,emitting UV radiation to the brush 8, is arranged above the brush 8 inorder to cure the material of the parts of the layer 2 adhering to thebristles in order to remove it out of the bristles, for example, at astripper edge (not shown) for cleaning the brush 8.

The cleaning of the brush 8 can basically be performed according to thedescription to FIG. 7.

After the brush 8 in the direction of motion, a further radiation source12 b is arranged. This radiation source 12 b emits, for example, UVradiation to the layer 2 and to an as possibly requested includedmanipulation medium 3 in order to perform a final curing.

FIG. 9 shows the removing of parts of the layer 2 with preceded andsubsequent cleaning of the layer 2 by a device in the form of aproduction line.

Two workpieces 1 moved from the left to the right by a transport devicehaving a conveyor transport 20 are shown. On the workpieces 1, a layer 2is applied.

Thereby, before the removing of parts of layer 2, first, a cleaningagent 16 is applied onto the layer 2 by means of an application device17, here comprising an application roller. Subsequently, this cleaningagent 16 is at least partially removed once again by a stripper 18.Subsequently, the removing of parts of the layer 2 by a stationarycontact element 15 and a brush 8 is performed, wherein a UV beam source12 is provided in order to irradiate the brush 8 and the contact element15 in order to cure or brittle the thereat adhering material of removedparts of the layer 2. By means of a suction device 7, these parts 13 arecontinuously sucked away as described above. Moreover, as described inFIG. 7, a stripper edge (not shown) can be provided.

Subsequently, a further cleaning of the residual surface 2 remaining onthe workpiece 1 is performed by means of a cleaning agent 16 a, anapplication device 17 a, and a device for removing the cleaning agent 16a once again. Thereto, the device for removing once again the cleaningagent 16 a comprises a stripper 18 a being in contact with the surfaceof the layer 2 and a suction device 19 a. The suction device 19 a isconfigured to suck away and discharge the cleaning agent 16 a held backon the stripper 18 a.

Such a suction device for removing the cleaning agent 16 can also beprovided at the first stripper 18.

FIG. 10 shows a workpiece 1 having a layer 2 on the surface of theworkpiece 1, wherein the layer 2 has at least partially been cured andnow comprises areas 2 a having a higher hardness grade and areas 2 bhaving a lower hardness grade, wherein these areas differ in thehardness grade about a factor of at least 1.5, preferably of at least 2.The here illustrated workpiece 1 having the layer 2 is, for example,further processed in one above-described method for surface processing.

FIG. 11 shows an exemplary flowchart of a method.

In a step S10, a layer is generated on a work piece as, e.g., shown inFIG. 10, wherein the layer has different hardness grades.

In step S12, the workpiece having the layer is moved to a removaldevice. Here, according to step S14, a contact between the surface ofthe layer and a contact element of the removal device is established.

Alternatively or additionally, according to step S15, a fluid flowhaving an optional solid body ratio is generated, wherein the fluid flowacts onto the surface of the layer, whereby parts of the layer areremoved or loosed.

According to S16, after the establishing of the contact between thesurface of the layer and a contact element according to step S14, arelative motion between the contact element and the surface isperformed, wherein parts of the layer are removed or loosened.

According to step S18, separating of the loosened parts of the surfaceof the layer from the residual layer is performed. This can beperformed, e.g., by sucking away, wiping away, or blowing away, or byanother suitable measure.

In step S20, cleaning of the surface of the layer by means of contactor, also, in a contactless manner and/or by deploying a cleaning agentis performed.

The method can be further developed by exchanging, omitting and/orrepeating several steps as well as by supplementing several steps.

The invention is not restricted to the here shown embodiments. Moreover,further devices and/or methods also corresponding to the invention canbe achieved by combining, exchanging, or omitting individual features.

For example, the configuration of FIG. 7 can be supplementary integratedinto the production line of FIG. 8 or provided instead of the chamber 4and/or the here-shown brush 8.

Also, when in the FIGS. 2, 7, and 8, brushes 8 in the form of rollerbrushes are provided, supplementary or alternatively, theimplementations of the brushes 8 of the FIGS. 3, 4, and 5 can beprovided.

All of the nozzles 6 shown in the FIGS. 1 and 8 can be configured toemit a fluid flow with or without solid bodies, as described above. Thefluid flow can include a gas and/or a liquid, wherein it especiallyincludes air and/or water.

The radiation sources shown in all of the figures can be configured to,alternatively or additionally to the electromagnetic radiation,particularly UV radiation, also emit another radiation, as, e.g.,electron radiation. The kind of radiation and/or the respectivewavelength is thereby selected depending on the composition of thematerial of the layer 2 and/or of the manipulation medium 3 and/ordepending on the desired effect of the radiation to the layer 2 and/orto the manipulation medium 3. Thus, for a complete curing, anotherwavelength and/or radiation can be deployed than if merely the viscosityof the layer 2 shall be changed in a previous step in order to, forexample, prevent blurring of the recesses inserted by the manipulationmedium 3.

All of the here-shown embodiments of the invention which at leastcomprise a brush 8 can further be configured such that the at least onebrush 8 is provided movably. Thereby, it is to be understood that the atleast one brush 8 can be moved actively in a predefined motion pattern.Therefore, for example, a disc brush can be provided at a pivotablesuspension.

LIST OF REFERENCE SIGNS

1 workpiece

1 a connection element

2 layer

3 manipulation medium

4 chamber

5 curing device

6 nozzle

7 suction device

7 a suction device

8 brush

9 direction of rotation

10 circulation direction

11 beam

12 radiation source

12 a radiation source

12 b radiation source

13 loosened parts of the layer

14 stripper edge

15 brush

16 cleaning agent

16 a cleaning agent

17 application device

17 a application device

18 stripper

18 a stripper

19 a suction device

20 conveyor transport

S10 method step

S12 method step

S14 method step

S15 method step

S16 method step

S18 method step

S20 method step

What is claimed is:
 1. Method for removing parts of a layer (2) on asurface of a workpiece (1), the method comprising the steps:establishing a mechanical contact between a contact element and thelayer (2) on the surface for removing parts (13) of the layer (2);physical separating of removed parts (13) of the layer (2) from theparts of the layer (2) remaining on the surface of the workpiece (1). 2.Method for removing parts of a layer (2) on a surface of a workpiece(1), the method comprising the steps: generating a fluid flow, preferredat an angle between 1° and 90° with respect to the layer (2), forremoving parts (13) of the layer (2); physical separating of removedparts (13) of the layer (2) from the parts of the layer (2) remaining onthe surface of the workpiece (1).
 3. Method according to claim 1,wherein the layer (2) on the surface of the workpiece (1) hasdifferences in hardness of at least a factor 1.5, preferably at least afactor 2, between harder areas (2 a) and less hard areas (2 b). 4.Method according to claim 1, wherein the physical separating of theloosened parts (13) of the layer (2) from the parts of the layer (2)remaining on the surface of the workpiece (1) is performed by suckingaway, wiping away, blowing away, or by a combination of these steps. 5.Method according to claim 1, wherein the layer (2) located on thesurface of the workpiece (1) and the contact element move relative toone another during removing of parts of the layer (2).
 6. Methodaccording to claim 1, wherein the contact element comprises a stationaryand/or moved brush (8, 15) and/or a grinding element and/or a planeelement, wherein, the brush (8) preferably comprises, at least as movedbrush (8), a disc brush and/or a roller brush and/or a brush band,and/or, as stationary brush (8), a beam (11) with brush trimming, and/orwherein the contact element, particularly the brush (8, 15), comprisestextile and/or plastic fibers, particularly nylon fibers, Anderton,and/or metal, particularly steel, brass or copper as bristles.
 7. Methodaccording to claim 1, wherein simultaneously to the establishing of themechanical contact between the contact element and the layer (2) on thesurface, and/or, simultaneously to the generating of the fluid flow ontothe layer (2), an irradiation of the layer (2) and/or of the contactelement and/or of the surroundings of the contact element in whichseparated parts of the layer (2) are located is performed preferably byelectromagnetic radiation.
 8. Method according to claim 1, wherein thecontact element (8, 15) is continuously cleaned during the physicalseparating, wherein the cleaning is preferably performed by use of acombination of an electromagnetic beam source (5, 12) and/or a suctiondevice (7, 7 a) and/or a mechanical chipping edge (14).
 9. Methodaccording to claim 2, wherein a nozzle (6) configured to generate afluid flow is continuously cleaned during the physical separating,wherein the cleaning is performed preferably by a combination of anelectromagnetic beam source (5, 12) and/or a suction device (7, 7 a)and/or one or several further drying devices or beam sources (5, 12).10. Method according to claim 1, wherein before the establishing of themechanical contact between the contact element and the layer (2),cleaning of the surface of the layer (2) is performed, and/or wherein,after the physical separating of parts of the layer (2), cleaning of theresidual layer (2) remaining on the surface of the workpiece (1) isperformed.
 11. Method according to claim 2, wherein before thegenerating of the fluid flow onto the layer (2), cleaning of the surfaceis performed, and/or, after the physical separating of parts of thelayer (2), cleaning of the residual layer (2) remaining on the surfaceof the workpiece (1) is performed.
 12. Method according to claim 8,wherein the continuous cleaning of the contact element, particularly ofthe brush (8), is performed by irradiation with UV radiation, preferablywith a wavelength between 180 and 400 nm, in combination with strippingoff cured residual components (13) from the separated parts of the layer(2) on a chipping edge (14) and a sucking away these residual components(13) by means of a suction device (7, 7 a).
 13. Method according toclaim 9, wherein the continuous cleaning of the nozzle (6) is performedby irradiation with UV radiation, preferably with a wavelength between180 and 400 nm, in combination with sucking away residual components(13) of the separated parts of the layer (2) by means of a suctiondevice (7, 7 a).
 14. Method according to claim 10, wherein for cleaningthe surface of the layer (2), a cleaning agent (16) which is removedonce again subsequently, particularly preferred by means of a stripper(18) and/or a suction device (19), is applied onto the layer.
 15. Devicefor performing the method according to claim 1, the device comprising: atransport device configured to transport a workpiece (1) to furtherelements of the device, and/or at least one further element of thedevice to the workpiece (1); as further element, a removal deviceconfigured to remove parts (13) of the layer (2) mechanically, preferredby a contact element, and/or in a fluidic manner, preferred by a fluidflow out of a nozzle (6), wherein the device further comprises a controlmeans configured to control the transport device and the furtherelements of the device in order to perform the method according toclaim
 1. 16. Method according to claim 2, wherein the layer (2) on thesurface of the workpiece (1) has differences in hardness of at least afactor 1.5, preferably at least a factor 2, between harder areas (2 a)and less hard areas (2 b).
 17. Method according to claim 2, wherein thephysical separating of the loosened parts (13) of the layer (2) from theparts of the layer (2) remaining on the surface of the workpiece (1) isperformed by sucking away, wiping away, blowing away, or by acombination of these steps.
 18. Method according to claim 2, whereinsimultaneously to the establishing of the mechanical contact between thecontact element and the layer (2) on the surface, and/or, simultaneouslyto the generating of the fluid flow onto the layer (2), an irradiationof the layer (2) and/or of the contact element and/or of thesurroundings of the contact element in which separated parts of thelayer (2) are located is performed preferably by electromagneticradiation.
 19. Device for performing the method according to claim 2,the device comprising: a transport device configured to transport aworkpiece (1) to further elements of the device, and/or at least onefurther element of the device to the workpiece (1); as further element,a removal device configured to remove parts (13) of the layer (2)mechanically, preferred by a contact element, and/or in a fluidicmanner, preferred by a fluid flow out of a nozzle (6), wherein thedevice further comprises a control means configured to control thetransport device and the further elements of the device in order toperform the method according to claim 2.